Arbitrary command execution in MS-DOS

Versions 1.1 and 2.0 of MS-DOS allow a malicious actor to execute arbitrary system commands via the main application interface. Prerequisites: * MS-DOS 1.1 or MS-DOS 2.0 installation * Input device (e.g. keyboard) Steps to reproduce: * Enter the _command mode_ * Type `VER` to make sure that the system is on of the affected versions * Pass a known system command like `HELP` to see that the system responds correctly * Use `EXEC PROGRAM_NAME.BAT` to execute arbitrary programs See PoC below.